'This book is based on twenty-five years of intensive study of patients in psychotherapeutic groups. The attitude is psychoanalytic but the method and technique are new. The background of consideration is the mental matrix of the group as a whole inside which all intrapsychic processes interact. This has a profound significance for psychoanalytical concepts and the many problems connected with them in psychoanalytic practice and theory.' - S.H. Foulkes, from the Preface